Alto de los Molinos

Overview

Alto de los Molinos is a genuine hors catégorie monster. At 26.1 km with an average gradient of 6.77%, it belongs to the small club of climbs long enough to reshape a whole ride around them. From a valley floor at 1096 m it drags you up to a summit of 2863 m — a net elevation gain of 1767 m and a total ascent of 1747 m, meaning almost every metre you climb is a metre you keep. There is very little false relief here.

Numbers alone earn this climb its HC label, but the shape is what makes it hurt: a sustained 6.77% average is punishing over such distance, and the max gradient of 23.25% tells you the road does not stay polite for its full length.

How the Gradient Unfolds

Think of Alto de los Molinos as a long, grinding baseline punctuated by cruelty. The 6.77% average is the rhythm you settle into, but averages hide the ramps. With a maximum pitch of 23.25%, there are moments where the road roughly triples its own mean gradient — the kind of wall that forces you out of the saddle whether you planned to stand or not.

Over 26.1 km, that combination matters. The steady stretches let you find a cadence; the spikes break it. The climb never lets you fully switch off. Because net gain (1767 m) and total ascent (1747 m) sit so close together, you get almost no recovery descents — the elevation profile trends relentlessly upward from 1096 m to 2863 m.

Pacing Notes

On a climb this long, pacing is everything. Ride the first third at an effort that feels almost too easy. A sensible target for the sustained sections is a percentage of your FTP — most riders can hold roughly threshold effort on a shorter climb, but across 26.1 km you should sit comfortably below it and save headroom for the 23.25% ramps.

If you do not know your threshold, run the numbers through the FTP estimator before you attempt this. Knowing your ceiling turns the steep pitches from a guessing game into a managed cost. Meter your surges over each ramp, then return immediately to your baseline effort rather than chasing lost time. At altitude near 2863 m, power comes harder than it does lower down, so give yourself margin.

Gearing

Gear for the walls, not the average. A compact 34-tooth chainring paired with a wide cassette is the honest choice here. On the more forgiving 6.77% stretches a 34×32 will spin fine, but the 23.25% pitches will crush a tired rider in anything too tall — so a 34×34 (or lower) gives you the bailout ratio you will be grateful for near the top. When in doubt on a 26.1 km HC climb, take the easier gear. Cadence preserved early is watts saved late.

Summary

Alto de los Molinos is a full-day objective: 26.1 km of climbing, 1767 m of vertical, and ramps to 23.25% that never fully relent. Pace it conservatively, gear it generously, and respect the thin air at 2863 m.

Length: 26.1 km
Average gradient: 6.77%
Max gradient: 23.25%
Start: 1096 m
Summit: 2863 m
Net gain: 1767 m
Total ascent: 1747 m
Category: HC